Prorate your mileage over each vehicle. In other words, enter the same total for each vehicle,
but claim prorated usage.
Lets say you claim 50% of your mileage is business, and of that, 25% was incurred on vehicle 1 and the rest on vehicle 2. So if your annual total is 30,000..
Vehicle 1 business use is 30,000 x 0.5 x 0.25 = 3750
Vehicle 2 business use is 30,000 x 0.5 x 0.75 = 11,250
